A study of cognitive function in treatment-refractory obsessive-compulsive disorder treated with capsulotomy

Anterior Capsulotomy for Refractory Obsessive-Compulsive Disorder: A Tractography and Lesion Geometry study

INTRODUCTION

A bilateral anterior capsulotomy effectively treats refractory obsessive-compulsive disorder (OCD). We investigated the geometry of lesions and disruption of white matter pathways within the anterior limb of the internal capsule (ALIC) in patients with different outcomes.

METHODS

In this retrospective study, we analyzed data from 18 patients with refractory OCD who underwent capsulotomies. Patients were grouped into "responders" and "nonresponders" based on the percentage of decrease in the Yale-Brown Obsessive-Compulsive Scale (YBOCS) after surgery. We investigated neurobehavioral adverse effects and analyzed the overlap between lesions and the ventromedial prefrontal (vmPFC) and dorsolateral prefrontal (dlPFC) pathways. Probabilistic maps were constructed to investigate the relationship between lesion location and clinical outcomes.

RESULTS

Of the 18 patients who underwent capsulotomies, 12 were responders (>35% improvement in YBOCS), and six were nonresponders. The vmPFC pathway was more involved than the dlPFC pathway in responders (p = 0.01), but no significant difference was observed in nonresponders (p = 0.10). The probabilistic voxel-wise efficacy map showed a relationship between ventral voxels within the ALIC with symptom improvement. Weight gains occurred in 11/18 (61%) patients and could be associated with medial voxels within the ALIC.

CONCLUSION

The optimal outcome after capsulotomy in refractory OCD is linked to vmPFC disruption in the ALIC. Medial voxels within the ALIC could be associated with weight gains following capsulotomy.

Evidence Accumulation and Neural Correlates of Uncertainty in Obsessive-Compulsive Disorder

BACKGROUND

Decision making is frequently associated with risk taking under uncertainty. Elevated intolerance of uncertainty is suggested to be a critical feature of obsessive-compulsive disorder (OCD). However, impairments of latent constructs of uncertainty processing and its neural correlates remain unclear in OCD.

METHODS

In 83 participants (24 OCD patients treated with capsulotomy, 28 OCD control participants, and 31 healthy control participants), we performed magnetic resonance imaging using a card gambling task in which participants made decisions whether to bet or not that the next card would be larger than the current one. A hierarchical drift diffusion model was used to dissociate speed and amount of evidence accumulated before a decisional threshold (i.e., betting or no betting) was reached.

RESULTS

High uncertainty was characterized by a smaller amount of evidence accumulation (lower thresholds), thus dissociating uncertainty from conflict tasks and highlighting the specificity of this task to test value-based uncertainty. OCD patients exhibited greater caution with poor performance and greater evidence accumulation overall along with slower speed of accumulation, particularly under low uncertainty. Bilateral dorsal anterior cingulate and anterior insula distinguished high- and low-uncertainty decision processes in healthy control participants but not in the OCD groups, indicating impairments in anticipation of differences in outcome variance and salience network activity. There were no behavioral or imaging differences relating to capsulotomy despite improvements in OCD symptoms.

CONCLUSIONS

Our findings highlight greater impairments particularly in more certain trials in the OCD groups along with impaired neural differentiation of high and low uncertainty and suggest uncertainty processing as a trait cognitive endophenotype rather than a state-specific factor.

Mechanisms underlying capsulotomy for refractory obsessive-compulsive disorder: neural correlates of negative affect processing overlap with deep brain stimulation targets

Ablative procedures such as anterior capsulotomy are potentially effective in refractory obsessive-compulsive disorder (OCD). Converging evidence suggests the ventral internal capsule white matter tracts traversing the rostral cingulate and ventrolateral prefrontal cortex and thalamus is the optimal target for clinical efficacy across multiple deep brain stimulation targets for OCD. Here we ask which prefrontal regions and underlying cognitive processes might be implicated in the effects of capsulotomy by using both task fMRI and neuropsychological tests assessing OCD-relevant cognitive mechanisms known to map across prefrontal regions connected to the tracts targeted in capsulotomy. We tested OCD patients at least 6 months post-capsulotomy (n = 27), OCD controls (n = 33) and healthy controls (n = 34). We used a modified aversive monetary incentive delay paradigm with negative imagery and a within session extinction trial. Post-capsulotomy OCD subjects showed improved OCD symptoms, disability and quality of life with no differences in mood or anxiety or cognitive task performance on executive, inhibition, memory and learning tasks. Task fMRI revealed post-capsulotomy decreases in the nucleus accumbens during negative anticipation, and in the left rostral cingulate and left inferior frontal cortex during negative feedback. Post-capsulotomy patients showed attenuated accumbens-rostral cingulate functional connectivity. Rostral cingulate activity mediated capsulotomy improvement on obsessions. These regions overlap with optimal white matter tracts observed across multiple stimulation targets for OCD and might provide insights into further optimizing neuromodulation approaches. Our findings also suggest that aversive processing theoretical mechanisms may link ablative, stimulation and psychological interventions.

Cognitive outcomes following functional neurosurgery in refractory OCD patients: a systematic review

Neurosurgery is a therapeutic option for patients with refractory obsessive-compulsive disorder who do not respond to previous treatments. Although its efficacy in reducing clinical symptomatology has been proven, few studies have analyzed its effects at the cognitive level. The aim of this systematic review was to describe the cognitive outcomes of functional neurosurgery in patients that went through capsulotomies or cingulotomies. PubMed, Medline, Scopus, PsycInfo, PsyArticles, and Web of Knowledge were searched for studies reporting cognitive outcomes in refractory obsessive-compulsive patients after capsulotomies and cingulotomies. The risk of bias was assessed with the Assessment Tool for Before-After (Pre-Post) Studies With No Control Group tool; 13 studies met inclusion criteria, including 205 refractory obsessive-compulsive disorder patients for both surgical procedures. Results showed a substantial number of studies that did report significant cognitive improvement after surgery, being this improvement specially related to memory and executive functions. The second-most frequent finding is the maintenance of cognitive performance (nor improvement or worsening). From a neuropsychological point of view, this outcome might be considered a success, given that it is accompanied by amelioration of obsessive-compulsive symptoms. Subtle cognitive adverse effects have also been reported. Neurosurgery procedures appear to be safe from a cognitive point of view. Methodological issues must be improved to draw clearer conclusions, but capsulotomies and cingulotomies constitute an effective alternative treatment for refractory obsessive-compulsive disorder patients.

Gamma knife capsulotomy for intractable OCD: Neuroimage analysis of lesion size, location, and clinical response

Obsessive-compulsive disorder (OCD) affects 2-3% of the population. One-third of patients are poorly responsive to conventional therapies, and for a subgroup, gamma knife capsulotomy (GKC) is an option. We examined lesion characteristics in patients previously treated with GKC through well-established programs in Providence, RI (Butler Hospital/Rhode Island Hospital/Alpert Medical School of Brown University) and São Paulo, Brazil (University of São Paolo). Lesions were traced on T1 images from 26 patients who had received GKC targeting the ventral half of the anterior limb of the internal capsule (ALIC), and the masks were transformed into MNI space. Voxel-wise lesion-symptom mapping was performed to assess the influence of lesion location on Y-BOCS ratings. General linear models were built to compare the relationship between lesion size/location along different axes of the ALIC and above or below-average change in Y-BOCS ratings. Sixty-nine percent of this sample were full responders (≥35% improvement in OCD). Lesion occurrence anywhere within the targeted region was associated with clinical improvement, but modeling results demonstrated that lesions occurring posteriorly (closer to the anterior commissure) and dorsally (closer to the mid-ALIC) were associated with the greatest Y-BOCS reduction. No association was found between Y-BOCS reduction and overall lesion volume. GKC remains an effective treatment for refractory OCD. Our data suggest that continuing to target the bottom half of the ALIC in the coronal plane is likely to provide the dorsal-ventral height required to achieve optimal outcomes, as it will cover the white matter pathways relevant to change. Further analysis of individual variability will be essential for improving targeting and clinical outcomes, and potentially further reducing the lesion size necessary for beneficial outcomes.

Functional interventions as augmentation strategies for obsessive-compulsive disorder (OCD): scoping review and expert survey from the international college of obsessive-compulsive spectrum disorders (ICOCS)

BACKGROUND

Patients with obsessive-compulsive disorder (OCD) commonly exhibit a range of functional difficulties, presumed linked to neurocognitive changes. Evidence-based first-line treatments have limited effect on improving these cognitive-functional problems. Candidate interventions could be used to augment evidence-based treatments by the multi-professional mental health team.

METHODS

A scoping review was performed to identify any intervention with at least one peer-reviewed report of clinical improvement in any of the 13 functional domains of the Cognitive Assessment Instrument of Obsessions and Compulsions (CAIOC-13). Next, an online survey of experts of the International College of Obsessive-Compulsive Spectrum Disorders was conducted.

RESULTS

Forty-four studies were identified reporting a positive outcome for 27 different kinds of intervention. Twenty-six experts from 12 different countries, including at least one expert from each continent, completed the opinion survey. Five interventions were identified as 'highly promising', none of which was moderated by rater-related factors, suggesting global applicability.

CONCLUSION

Patients with OCD may benefit from a detailed functional assessment, to identify areas of unmet need. A variety of interventions show theoretical promise for treating the complex functional difficulties in OCD as adjuncts to first-line treatments, but the published evidence is weak. Randomised controlled trials are needed to determine the clinical effectiveness of these interventions.HighlightsFunctional-cognitive problems are common in patients with OCD.First-line evidence-based treatments have limited effect on these functionalcognitive difficulties.In our scoping review we found 44 studies reporting of improved clinical outcomes in any of the 13 functional domains of the Cognitive Assessment Instrument of Obsessions and Compulsions (CAIOC-13).An online survey of experts of the International College of Obsessive-Compulsive Spectrum Disorders (ICOCS) was conducted and identified five interventions as "highly promising" candidate treatments for functional-cognitive problems in OCD.Randomised controlled trials are needed to determine the clinical effectiveness of these interventions.

Interstitial laser anterior capsulotomy for obsessive-compulsive disorder: lesion size and tractography correlate with outcome

BACKGROUND

Anterior capsulotomy is a well-established treatment for refractory obsessive-compulsive disorder (OCD). MRI-guided laser interstitial thermal therapy (LITT) allows creation of large, sharply demarcated lesions with the safeguard of real-time imaging.

OBJECTIVE

To characterise the outcomes of laser anterior capsulotomy, including radiographical predictors of improvement.

METHODS

Patients with severe OCD refractory to pharmacotherapy and cognitive-behavioural therapy underwent bilateral anterior capsulotomy via LITT. The primary outcome was per cent reduction in Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score over time. Lesion size was measured on postablation MRI. Disconnection of the anterior limb of the internal capsule (ALIC) was assessed via individual and normative tractography.

RESULTS

Eighteen patients underwent laser anterior capsulotomy. Median follow-up was 6 months (range 3-51 months). Time occupied by obsessions improved immediately (median Y-BOCS item 1 score 4-1, p=0.002). Mean (±SD) decrease in Y-BOCS score at last follow-up was 46%±32% (16±11 points, p<0.0001). Sixty-one per cent of patients were responders. Seven patients (39%) exhibited transient postoperative apathy. One patient had an asymptomatic intracerebral haemorrhage. Reduction in Y-BOCS score was positively associated with ablation volume (p=0.006). Individual tractography demonstrated durable ALIC disconnection. Normative tractography revealed a dorsal-ventral gradient, with disconnection of orbitofrontal streamlines most strongly associated with a positive response (p<0.0001).

CONCLUSIONS

Laser anterior capsulotomy resulted in immediate, marked improvement in OCD symptom severity. Larger lesions permit greater disconnection of prefrontal-subcortical pathways involved in OCD. The importance of greater disconnection is presumably related to variation in ALIC structure and the complex role of the PFC in OCD.

Cognitive deficits and clinical symptoms in patients with treatment-refractory obsessive-compulsive disorder: The role of slowness in information processing

Patients with Obsessive-Compulsive Disorder (OCD) present neuropsychological deficits across different cognitive domains, especially in executive functioning and information processing speed. Some studies have even suggested that speed deficits may underlie poor neuropsychological performance. However, this hypothesis remains unanswered in both OCD general population and OCD refractory subgroup. In addition, it is not clear whether such deficits are secondary to the clinical symptoms or may constitute a primary deficit. The aim of this study was to explore the speed of processing hypothesis in treatment-refractory OCD patients, and to clarify to what extent slowness is related to psychopathological symptoms. Both clinical and neuropsychological examination was conducted to assess 39 OCD refractory patients candidates for neurosurgery and 39 healthy matched individuals. Principal component analysis revealed a three-component structure in the neuropsychological battery being used, including a speed of processing, working memory, and conflict monitoring components. Group comparisons revealed that OCD patients performed significantly worse than healthy individuals in speed measures, but no differences were found in executive tests not influenced by time. Correlation analyses revealed a lack of association between neuropsychological and clinical measures. The results suggest that treatment-refractory OCD patients exhibit a primary deficit in information processing speed independent of clinical symptoms.

Neuropsychological outcome in refractory obsessive-compulsive disorder treated with anterior capsulotomy including repeated surgery

AIM

Anterior capsulotomy (AC) is one of the last therapeutic options for obsessive-compulsive disorder (OCD) refractory to conservative treatments. Several forms of cognitive dysfunction have been identified after assessment of neuropsychological outcomes in OCD patients; however, few studies focused on cognitive changes in OCD patients after surgery. In the present study, we evaluated the effects of AC on cognitive performance and mood status in patients with refractory OCD.

METHODS

A total of 12 patients underwent bilateral AC between 2012 and 2019 at our institution. The patients (n = 12, female : male 5:7; mean age 39.7 years; duration ≥5 years) were assessed before and 6 months after intervention. The diagnosis of treatment-refractory OCD was based on recommended criteria for surgical treatment. Patients were assessed using a neuropsychological battery and questionnaires focused on anxiety-depressive symptomatology. The Yale-Brown Obsessive Compulsive Scale was administered as a measure of severity of OCD symptoms.

RESULTS

We detected a significant decrease of OCD, and anxiety and depressive symptomatology assessed by Yale-Brown Obsessive Compulsive Scale, Beck Depression Inventory, and Beck Anxiety Inventory (P < 0.05) 6 months after AC in eight patients, and a partial decrease in four patients. Four patients underwent repeated AC with more pronounced improvement achieved after the first procedure. We did not detect decline in cognitive performance in any patients, but did find better visual memory performance (P < 0.05).

CONCLUSION

AC reduced OCD and anxiety-depressive symptoms, and did not appear to influence cognitive performance, even after repeated surgery.

Effectiveness and safety of neuroablation for severe and treatment-resistant obsessive-compulsive disorder: a systematic review and meta-analysis

Background

Several neuroablative procedures are available for severe and treatment-resistant obsessive-compulsive disorder (OCD), but limited knowledge about their relative clinical advantages and disadvantages poses obstacles for treatment decision-making.

Methods

We searched PubMed, Embase, Scopus, Web of Knowledge and the Cochrane Library for reports up to February 2019. We reviewed the literature on the effectiveness (assessed using the Yale-Brown Obsessive Compulsive Scale [Y-BOCS]) and safety of various neuroablative interventions for severe and treatment-resistant OCD.

Results

We included 23 studies involving 487 patients in the systematic review; 21 studies with 459 patients entered meta-analysis. Overall, neuroablation achieved a response rate (proportion of patients with ≥ 35% reduction in Y-BOCS) of 55%. Most of the adverse events (88.4%) were mild and transient. The top 3 adverse events were headache (14.9%), cognitive deficits (9.1%) and behaviour problems (8.1%). Severe or permanent adverse events included personality changes (2.3%) and brain edema or brain cyst (1.5%). The response rates associated with capsulotomy, limbic leucotomy and cingulotomy were 59% (95% confidence interval [CI] 54-65), 47% (95% CI 23-72) and 36% (95% CI 23-50), respectively. Interventions with different coverages of the dorsal part of the internal capsule were associated with different adverse-event profiles but were unlikely to modify clinical effectiveness.

Limitations

The level of evidence of most included studies was relatively low.

Conclusion

Ablative surgeries are safe and effective for a large proportion of patients with severe and treatment-resistant OCD. Among the available procedures, capsulotomy seemed to be the most effective. Further research is needed to improve clinical effectiveness and minimize risks.

An International Radiosurgery Research Foundation Multicenter Retrospective Study of Gamma Ventral Capsulotomy for Obsessive Compulsive Disorder

BACKGROUND

Obsessive compulsive disorder (OCD) across its full spectrum of severity is a psychiatric illness affecting ∼2% to 3% of the general population and results in significant functional impairment. There are few large patient series regarding Gamma ventral capsulotomy (GVC).

OBJECTIVE

To evaluate clinical outcomes of severe medically refractory OCD treated with GVC.

METHODS

This is an international, multicenter, retrospective cohort study. Forty patients with pre-GVC Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores ≥ 24 (indicating severe OCD) were included. GVC was performed with 1 or 2 isocenters with a median maximum dose of 135 Gy (range, 120-180 Gy). Patients were deemed "responders" to GVC if there was ≥35% reduction of follow-up Y-BOCS scores, and considered in remission if their Y-BOCS scores were ≤16. The median follow-up was 36 mo (range, 6-96 mo).

RESULTS

The median pre-SRS Y-BOCS score was 35 (range, 24-40). Eighteen patients (45%) were considered "responders," and 16 (40%) of them were in remission at their last follow-up. Nineteen patients (47.5%) remained stable with Y-BOCS of 33 (range, 26-36) following GVC, whereas 3 patients (7.5%) experienced worsening in Y-BOCS scores. Patients treated with 2 isocenters were more likely to have improvement in Y-BOCS score at 3 and 5 yr (P < .0005). Ten patients (25%) experienced post-GVC mood disturbance and neurological complications in 3 patients (7.5%). One patient developed radiation necrosis with edema that improved with steroids.

CONCLUSION

GVC serves as a reasonable treatment strategy for severe medical refractory OCD. Patients treated with 2 isocenters were more likely to have substantial improvement in OCD.

Ablative neurosurgery and deep brain stimulation for obsessive-compulsive disorder

Despite advancements in pharmacotherapeutic and behavioral interventions, a substantial proportion of patients with obsessive-compulsive disorder (OCD) continue to have disabling and treatment-refractory illness. Neurosurgical interventions, including ablative procedures and deep brain stimulation (DBS), have emerged as potential treatment options in this population. We review the recent literature on contemporary surgical options for OCD, focusing on clinical aspects such as patient selection, presurgical assessment, and safety and effectiveness of these procedures. Given the invasiveness and limited evidence, these procedures have been performed in carefully selected patients with severe, chronic, and treatment-refractory illness. Along with informed consent, an independent review by a multidisciplinary team is mandated in many centers. Both ablative procedures and DBS have been found to be helpful in around half the patients, with improvement observed months after the procedure. Various targets have been proposed for either procedure, based on the dominant corticostriatal model of OCD. There is no strong evidence to recommend one procedure over the other. Hence, the choice of procedure is often based on the factors such as affordability, expertise, and reversibility of adverse effects. Surgery is not recommended as a standalone treatment but should be provided as part of a comprehensive package including medications and psychotherapeutic interventions. Available evidence suggest that the benefits of the procedure outweigh the risks in a treatment-refractory population. Advances in neurosurgical techniques and increasing knowledge of neurobiology are likely to bring about further progress in the efficacy, safety, and acceptability of the procedures.

Effects of Anterior Capsulotomy on Decision Making in Patients with Refractory Obsessive-Compulsive Disorder

Despite various lines of evidence implicating impaired decision-making ability in individuals with obsessive–compulsive disorder (OCD), neuropsychological investigation has generated inconsistent findings. Although the cortico-striato-thalamo-cortical (CSTC) circuitry has been suggested, the involvement of the cortex has not yet been fully demonstrated. Moreover, it is unknown whether surgical intervention on the CSTC circuitry results in a predicted improvement of decision-making ability of OCD. Here we present a study of decision making based on the Iowa Gambling Task (IGT) to investigate decision making in a large sample of individuals with treatment-resistant OCD with and without anterior capsulotomy (AC). Task performance was evaluated in healthy subjects, individuals with OCD that had not undergone surgery, and postsurgical OCD patients with AC. The latter group was further divided into a short-term postsurgical group and a long-term postsurgical group. We found that the OCD patients without surgery performed significantly worse than the healthy controls on the IGT. There were no significant differences in decision-making between the presurgical OCD patients and those at the short-term postsurgical follow-up. Decision-making ability of the long-term postsurgical OCD patients was improved to the level comparable to that of healthy controls. All clinical symptoms (OCD, depression, and anxiety) assessed by psychiatric rating scales were significantly alleviated post-surgically, but exhibited no correlation with their IGT task performance. Our findings provide strong evidence that OCD is linked to impairments in decision-making ability; that impaired CSTC circuitry function is directly involved in the manifestation of OCD; and that AC related improvements in cognitive functions are caused by long-term plasticity in the brain circuitry.